A substantial proportion of the swine produced in North America today are produced utilizing artificial insemination. Thus, the ability to preserve animal reproductive samples, such as semen, oocytes and embryos, for use in artificial insemination and other reproductive processes is important. Without this ability, it is not possible to transport animal reproductive samples or store the samples for any length of time; thus, the utility of the samples is limited.
To protect reproductive samples from bacterial contamination, it has been common practice to introduce antibiotics into the preservation mediums or extender solutions. Although conventional antibiotics can be a low cost and effective way of preserving the samples, there are long term consequences of the continued widespread use of antibiotics. Over time, bacteria come to the fore which are resistant to antibiotics. The presence of low levels of antibiotics in agricultural livestock and human food products is considered to be one cause of the increasingly resistant bacteria. The increased resistance of bacteria to antibiotics poses a danger to humans and animals as infectious diseases are becoming more difficult to treat. Hence, in certain regions, conventional antibiotics are no longer effective. Moreover, there is consideration being given by regulatory bodies to banning the general use of antibiotics in animals raised for food production. Thus, it is desirable to have an extender that has antimicrobial properties, but is substantially free of antibiotics. It is also desirable to have a method for preserving animal reproductive samples that uses an extender that has antibicrobial properties, but is substantially free of antibiotics.
The method of this invention mixes a colloidal suspension of silver as a component of a preservation medium for the preservation of animal reproductive samples. By adding the colloidal suspension of silver to conventional semen extenders, for example, an extender for boar semen which has antimicrobial properties, but substantially free of antibiotics is produced. A colloidal silver solution having a silver concentration of at least about 1xc3x9710xe2x88x929 moles/liter has been found effective in preserving some reproductive materials.
It is an object of the present invention to provide an extender with antibacterial and antiviral properties without the use of antibiotics.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Not applicable.